A conventional system or device for displaying an image, such as a display, projector, or other imaging system, is frequently used to display a still or video image. Viewers evaluate display systems based on many criteria such as image size, contrast ratio, color purity, brightness, pixel color accuracy, and resolution. Image brightness, pixel color accuracy, and resolution are particularly important metrics in many display markets because the available brightness, pixel color accuracy, and resolution can limit the size of a displayed image and control how well the image can be seen in venues having high levels of ambient light.
A conventional display system produces a displayed image by addressing an array of pixels arranged in horizontal rows and vertical columns. Because pixels have a rectangular shape, it can be difficult to represent a diagonal or curved edge of an object in a image that is to be displayed without giving that edge a stair-stepped or jagged appearance. Furthermore, if one or more of the pixels of the display system is defective, the displayed image will be effected by the defect. For example, if a pixel of the display system exhibits only an “off” position, the pixel may produce a solid black square in the displayed image. The undesirable results of pixel geometry and pixel inaccuracy are accentuated when the displayed image is projected onto a large viewing surface in color.
Many display systems create a full color display with a single modulator by creating three or more modulated images in primary colors (red, green, and blue) per video frame. The primary colors are typically derived from a white light source using a color wheel, prism, or some other color filter. The modulated images are sequentially displayed at a high rate so as to create a full color image in the human visual system. Thus, this method of generating a full color display is called “sequential color.” Although the use of sequential color yields the desired red, green, and blue light for image formation, it does so by blocking the transmission of undesired light wavelengths. In other words, a significant portion of the light emitted by the light source is wasted, resulting in a decreased brightness of the final displayed image.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.